something that happens, an occurance or event. it is used specifically in inquisition, and is featured in the motion picture Joe Dirt.
A bro, or brosky, will walk through your front door unbeknownst to you with a twelve pack of rolling rock or corona, at which point you exclaim: "What's crappening?!"
When something crappy happens.
I can't believe this is crappening to me right now.